I am a woman who experienced the same thing your wife went through. Feeling unsatisifed with my life for no good reason. I ended up having an affair and when caught didn't admit it. Of course we couldn't deal with it as I denied it. After a couple of months, my husband pretty much forced me to leave. I got an apt and had a relationship over that period with a younger man and although we cared for each other very much, he was looking for marriage and children and I knew it had to end. In the mean time, my husband filed for divorce, worked on himself by going to the gym and keeping very busy with our boys and house projects. He began to feel better about himself and started dating. I became scared that I had made a huge mistake. I begged him to give me one more chance. Against his better judgement, he let me come back. It has been 4 months and it has been very difficult for both of us. We are in therapy with a wonderful psycpologist who is caring, really litens, and offers ways for us to communicate. His ultimate goal for us is to have no regrets which ever way we end up. whether it is together or apart. We both feel comfortable with him and feel as if he does us a world of good. Also, we see him alone too so he can get a better perspective on our relationship. I don't know what is going to happen with us but I feel that this is a positive step for both of us no matter what happens.
My point to you is stop focusing on her so much. If you can possibly do so, get her out of the house and on her own. Let her see how it is to be on her own. then you can focus on yourself, your boys, and your home. Take one thing at a time and make it a project for yourself. You will begin to feel better about yourself. File for the divorce and put the ball in her court. It's not worth living with someone who doesn't want to be with you. You deserve to be happy and so does she. If that means that you have to be apart, so be it. It can be very intoxicating to have two men going after you. Take yourself out of the equation. You deserve better than being the consolation prize. Not to mention that it can't be a very healthy environment for your children to live with such tension. Do NOT let her live with you and continue her affair hoping it will end. You are allowing her to have her cake and eat it too. In a way you are enabling her. Get tough and put youself and your children first. Don't put her first. she is already doing that. Going through MLC can turn an otherwise loving, caring person into a selfish, self-centered person. Hopefully she will wake up one morning, reflect on her actions and try to make things right; turn them around. In the meantime, you may find that life is better witout her and all her drama.
I Wish you the best of luck.
From A Woman Like Your Wife